Fingerprint authentication is used for identity verification or the like when making a log-in to a PC (Personal Computer), entering a room, or the like, for example. Recently, the fingerprint authentication is also used when unlocking a mobile terminal such as a smartphone, a tablet terminal, or the like, for example.
A fingerprint sensor that is used for the fingerprint authentication when making the log-in to the PC may be built into the PC, or connected to the PC via an external USB (Universal Serial Bus) cable. In either case, it is rare for a position of the fingerprint sensor to greatly change every time the fingerprint authentication is performed. In addition, in a case in which the fingerprint authentication is used for the identity verification when entering the room, the fingerprint sensor is fixed to a wall or the like at an entrance of the room, and it is rare for the position of the fingerprint sensor to greatly change every time the fingerprint authentication is performed.
On the other hand, in a case in which the fingerprint authentication is performed on the mobile terminal having the built-in fingerprint sensor, a fingerprint data that is input may vary every time the fingerprint authentication is performed depending to a manner of holding the mobile terminal by the user, and the fingerprint authentication may fail.
A method of stabilizing a fingerprint matching result in a case in which a manner of inputting the fingerprint data (for example, acceleration, pressure, or the like of a user's finger with respect to the fingerprint sensor) differs, includes a proposed technique that adjusts a sensitivity of the fingerprint sensor according to the manner of inputting the fingerprint data. However, in the mobile terminal, the manner of holding the mobile terminal varies when the user performs the fingerprint authentication, and it is difficult to reduce the failure of the fingerprint authentication by merely adjusting the sensitivity of the fingerprint sensor according to the manner of inputting the fingerprint data.
In addition, in biometric authentications other than the fingerprint authentication using the mobile terminal, it is difficult to reduce the failure of the biometric authentication due to reasons similar to those described above for the fingerprint authentication. The biometric authentications other than the fingerprint authentication include authenticating biometric data such as a vein pattern of a palm, a vein pattern of a finger, a palm-print pattern, an iris pattern of an eye, or the like, for example. These biometric data may be input using a sensor, a camera, or the like.
Related art include methods and apparatuses proposed in Japanese Laid-Open Patent Publications No. 2013-239139, No. 2006-011591, and No. 2007-249797, for example.
When performing the biometric authentication by the mobile terminal, it is thus difficult to reduce the failure of the biometric authentication, because the manner of holding the mobile terminal by the user varies in addition to the manner of inputting the biometric data, every time the biometric authentication is performed.